Reverse 911

Reverse 911 is a public safety communications system developed by Cassidian Communications, formerly PlantCML, a unit of EADS North America.[1][2] It is used by public safety organizations in Canada and the United States to communicate with groups of people in a defined geographic area. The system uses a database of telephone numbers and associated addresses, which, when tied into geographic information systems (GIS), can be used to deliver recorded emergency notifications to a selected set of telephone service subscribers.[3]